Solid-phase synthesis of 3,4-dihydro-2(1H)-quinazolinones and 3,4-dihydro-1H-quinazolin-2-thiones

The solid-phase synthesis of 3,4-dihydro-2(1H)-quinazolinones and 3,4-dihydro-1H-quinazolin-2-thiones is described. Starting from Rink resin, acylation with 4-bromomethyl-3-nitrobenzoic acid and amination with primary amines, reduction with tin chloride and cyclization, the desired 3,4-dihydro-2(1H)-quinazolinones and 3,4-dihydro-1H-quinazolin-2-thiones have been synthesized in good yield and high purity.